In the medical field, etc., a lot of studies of antimicrobially-processed fiber products are made for preventing infection and for keeping hygienic conditions.
Patent Reference 1 discloses a sheet prepared by incorporating a carboxymethyl cellulose quaternary ammonium salt or a carboxymethyl cellulose chlorohexidine salt in wood pulp, non-wood pulp, rayon fiber, synthetic fiber, carbon fiber or the like by combined sheeting, etc. The reference says that its antimicrobial effect lasts longer than that of a sheet produced by mere antimicrobial impregnation.
On the other hand, Patent Reference 2 discloses an antimicrobial polymer composition comprising a polymer having a functional monomeric unit and an antimicrobial agent attached to the functional monomeric unit, and describes, as its example, one that comprises a quaternary ammonium salt and a cationic dye attached to an acrylic fiber.
However, it is difficult to say that the antimicrobial potency of the antimicrobial fibers described in these patent references may be sufficient.
Patent Reference 3 discloses an antimicrobial deodorizing fiber obtained by kneading a silver compound, as an antimicrobial agent, into a fiber material rich in adsorbability such as an acrylic fiber, then spinning it, and dipping the resulting fiber in a quaternary ammonium salt solution.
However, the antimicrobial deodorizing fiber is problematic in that the durability of the antimicrobial and deodorizing potency thereof is not sufficient and the effect of the antimicrobial agent in the fiber could not be fully exhibited.
Clothing such as uniforms; linens such as sheets, towels; dust control products such as mops, entrance cloths, dust mats, air conditioner filters, and others are collected and recovered, such as washed and finished, and reused, so as not to dispose of used fiber products from the viewpoint of effective utilization of natural resources, reduction in the environmental load, energy saving and the like. The regeneration and reuse are also carried out for fiber products for medical applications such as surgical clothing.
It is important that such regeneration and reuse does not provide a hygienic problem; but in a process of regeneration, the antimicrobial potency may be often lowered or lost. This may be because in the process of regeneration, the antimicrobial component may drop off from the fiber products.
Patent Reference 1: JP-A-5-43409
Patent Reference 2: JP-T-2004-509220 (WO2002/022923)
Patent Reference 3: JP-A-5-195438